Screw driver



P. RQBERTsoN scREw DRIVER Filed sept 20 1944 .5. Fly-9 fly? The linve1'ltion`=relatesft Y'firiiprovements inscrew driversiand yparticularly to.` a type of screw-driven adapted yfor;` use in* driving-#socketor recessed I *i headed screws f and the principle object ofthe in:

providing avariety of points orftips to itvarious sizes of socket screws readily available forthe workman with the least possible expenditure of time. b

A further Objectis to devise an inexpensive tool structure of extremely simple and accurate construction in which removable or exchangeablebits,

will be rigidly held for operative use and may be easily and quickly released and removed.-

Theprincipal feature of theinvention consists.Y

cured by a constricting chuck mounted uporlthe;

slotted tube.` z 1 l vIn the accompanying drawing,Figurelisgan elevational, view of a Vscrewdriver constructed in accordance with the present invention, M

Figure 21s` an enlarged longitudinal midf-'sec-I tional view of a portion of the tubular bit-holding member of the screw driver illustrated in Figure 1.

Figure 3 is an end elevational View of the driver shown in Figure 2.

Figure 4 is a cross section through the driver taken on the line 4--4 of Figure 2.

Figure 5 is an elevational detail of one type of dual purpose bit.

Figure 6 is an end view of the bit shown in Figure 5.

Figures 7, 8 and 9 are elevational views of screw drivers constructed similar to Figure 1 having different forms of shank ends for engagement with standard driver handles or tools.

Figure 10 is a. longitudinal sectional view of a short type of screw driver constructed in accordance with this invention.

Several sizes of socket head screws are obtainable in the open market and it is well known that the dimensions of the sockets vary in accordance with the sizes of the screws. These socket sizes are usually divided into three sizes and normally it is necessary for a workman to be provided with screw drivers of three separate sizes in order that he may handle the various sizes of screws which he may encounter in the course of his work.

It will be readily understood that such conditions will result in much loss of time in locating the proper sized driver and frequently one or other of such drivers may be mislaid and much inconvenience results.

It is extremely desirable that a workman be provided with a tool which will enable him to have `Parentflorence all'sizeslof bits thatlinay be required readily available lso`tl`iat` lie-may Aquickly change from one to the other and which will hold the bits rigidly s0 that his work may lnot be impaired.

` lrl'n carrying this' invention into effect I construct the'driver-'bits I' from parallel multi-faced steel preferably of"s`quare cross 'section and the ends of-such bitsl'are shaped with socket tting tips 2, 3 'andll of diniensionssuitable for the screw sock- `ets"whichwill be' encountered.

Bits lare also preferably formed with ilat tips 5 adaptedto enter A"the slots of ordinary slotted screwslwww 2., t :EN ,1.

"It wil'lbe seenon referencet Figure 2 that two bits' willpro'vide iourdiiiere'ntsizes and kinds of tips'; and 'b'othbit'sareformed of stock square in cross section, and preferably of the dimensions of 'the"-largest Ytype of square socket screw. The bit Iend 5 is bevelled angularly from two corners solthatl itpresentsfa fiat tip across the diagonal dimension of the Abit stock. This arrangement permitsits use'in al slot type screw and the angled corners wil-lffit into' thecorners' of a Square socket screw.' 1'

-The second bitI withwhich a driver is equipped is `formed with thereduced-ends 3 and 4 to iit other sizes 'of sockets. 1

The shank 6 of the' driveris made from tubular stock; oneendof-which isv'b'edded in the handle 1 :fand the outer endy is formedfwith" a threaded portion 8 adjacent to the extremity upon which a chuck collar 9 is threaded.

The tubular member 6 is preferably slightly reduced in diameter beyond the threaded portion 8 and has a bevelled surface Ill which is engaged by a bevelled surface II on the inner wall of the collar 9.

The tube 6 is .preferably slotted with diagonal cross slots I2 which extend longitudinally for a length approximately the length of two of the bits and the angled longitudinal corners of the bits enter and slide longitudinally in the said slots.

The tubular shank is reamed for a distance slightly past the inner ends of the slots I2 and a shoulder I3 is thus formed.

A cylindrical block I4 slidable within the reamed bore of the tubular shank is adapted to engage the shoulder I3 and forms an `anvil against which the inner of the bits inserted into the slotted shank engages.

A collar I5 slidably encircling the tubular shank is connected to the anvil block It by a cross pin I6 extending through one of the slots and with said block forms an ejector for removing the bits from the shank.

It will be understood that when the angle-faced bits are slipped into the slotted shank with their longitudinal corners entering the longitudinal slots, the slot edges form sliding guide surfaces and upon the tightening of the chuck collar 9 against the bevel surfaces adjacent to the outer end of the shank, the slot edges Will be pressed into tight gripping contact withlthesides of the bit. Thisgrippingffisnot however allepepxdf'i'uponlvl 5 to take the full working thrust of th screw driver,

as the anvil block, bedded against the shoulderv I3 in the shank forms a solid abutment to take the thrust.

The tool thus described provides bits with all lo desired sizes of tips and in orderttolchangelfrom; one to another it is merelyneeessaryv to-lopsen the chuck collar then push gain's't't cou'ar l5 moving the anvil block to push the bits outwardf ly. The desired tip is then selected and the bits returned tweewieler Shemalerearrangemention :andf i'iponA tightening; the.v struck;- 'collars it A,` ls s again ready for use.

Ih Certain typeslofldriverswhereshgrt leegte is required; Such-es :isf- Shvowplfsie-Fleilrefllr the collar I3fwith its cross,pintthroughthe/,anviikj block-,may bedispepsedwithl Insuchcopfstiu tion the anvil block:maylbeikma'defajtight iitlin, the reemed eedloathemeer@iwleerpfsee Y against the shoulderlfj ittwii'l reinai A; `v provides a solid anvil surface inthe t to receive the end thrustagafinstthe .itsV

Figures '7, `8 and 9 illustrate the applicationypt this invention to varioustypesofdshanl` ends tlriat are( used to :litIvarious.commercialhtopls such a Yankeer driver, an eletricl driver l or; an5 ordinary bracef driver, M A A The adaptationv of a:,tubularshanlg/enables a5 driver being made with a/fwellf'or reges whiehany desired numberfof bits .mevr-bah so that they will be readilyavailable."

It will be readily understood. that rwhiilebitsg of square cross section Vare sliovvnfv` otherL angular crossA section shapes inay be used to `the -s1a| advantage. Also the bits shown are ,agiaptedV or square socket screws vbut tha-bits maytbe inagefrpf, other shapes to t other socketsysuohn,asxcrossedil slot sockets or socketsof otljier forms.

A tool such as described Shrof .e'xtrernelyprag; v

tical Valueand4 is neat arnjpemalsyl,to handig?,

What I claim as my invention is:

A screwdriver comprising a tubular shank having an enlarged bore extending inwardly from one endA thereof and defining an" annular shoulder andi haring lozligitudiiiegl i slats arranged in diametricalj1 opposite pairs extending inwardly from said end, a plurality of bits of square cross section arranged in axial end-to-end engagement inisaidshank and presenting longitudinal edges engaging in said slots maintaining said bits against rotation, an-anvil block slidably arranged inqsaidshankandengaging the inner end of the innermost of said bits, neans to operate said anvil blocletoladvance all of said bits toward the operating end of said tubular shank to adjustably expqsateeuiermest ofeid zbitseendmeensltolock Iigerinost of Vvsaid bits fromnmovement@lon,gify `llyof);said;shank;1in, adJ'llSledexposed1101511A l.

tion. Seide eerih blacks When,A .re.trzreteckA engesina sedfsheulderw receive through Seid bits arranged-i in ndfto-:end f relation the thrust against1- their @terme/Sabin PETER! L. aoenefrson.,

REEEEONQESCHeD;

The following .f references are ofrec0rdin thel` UNITED SrArEsf-.PATENTe Nurnber 

